I am a boating enthusiast (some would say nut) and I enjoy looking at and learning about all types of boats. Recently I traveled to the community of Gambel for work and while I was there I had a chance to look at some of the skin boats that they use there.
Gambel is located on St Lawrence Island, way out in the middle of the Bering sea. Gambel is one of the villages in this area that actively hunts bow head whales. I think that a lot of the hunting is now done from modern aluminum (Lund) boats, but there appears to still be a few traditional oomiaks being used.
All of the boats that I looked at were constructed the same and were basically the same size. About 24' long, 6' wide, and 3' deep. The keel timber measures about 3"x6" with a separate 2"x2" piece that goes on after the skin. The ribs are 1"x1" and the longitudinals are 3/4"x1 1/2". There is one clench nail at each intersection. The ribs are mortised into the gunwale piece, which measures about 2"x3". The ribs are made in halves and overlap slightly at the keel.
All the boats have a motor well in the same location, to one side of the keel about 5' from the stern. A small outboard motor can put dropped into this well. The outboard is used for traveling to and from the hunting area. When hunting they try to be as quiet as possible and they use a simple sail for propulsion. The sailing rig uses a wooden mast about 4" in diameter and 20' long. The mast is supported by a hinged mast partner that allows the mast to be slipped into place horizontally and then stood up.
This boats are what I would call "modern" oomiaks. These boats use metal fittings and a few other manufactured parts. Traditional boats would all be lashed together without any screws or nails. Many of the boats still have a covering made from split walrus or bearded seal skin. Some of the boats are covered with some kind of synthetic material (nylon, etc) covered with a few coats of thick paint.